you cannot ban a decentralized system. these ban are related to exchanges and money laundering activities (I guess), so in most part they want hit this type of economies related to bitcoin.
Because China is a foreign exchange control country, bitcoin anonymous online transactions can perfectly bypass the central bank's foreign exchange defense line, making foreign exchange control a negligent policy and providing great convenience for money laundering transactions in areas under strong domestic control. The big threat to China's central bank's foreign exchange policy and regulatory policies.